1819.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



217 



REGISTER OF NEW PATENTS. 



ELECTRIC TELEGRAPHS. 



Frederick Com.ier Bakewell, of Hampstead, for '•'■ improve- 

 ments in making communications from one phice to another bi/ means of 

 elcitricity."— Granted December 9, 184.8; Enrolled June 2, 1849. 



This invention consists, in the first place, of methods of copying', 

 by means of electricity, written or printed charactei-s for tele- 

 graphic communications; and, secondly, of modes of breaking and 

 renewing the electric circuits with different stations, so as to corre- 

 spond only with the place required. 



To carry out the first part of the invention, two or more instru- 

 ments are made as exactly alike as possible, so as to give equal 

 motions to a cylinder on each instrument. Parallel to the cylinder 

 is a screw, which carries a traversing nut from end to end as the 

 cylinder revolves. To the nut an arm is attached, at the end of 

 which there is a metal style or point that presses on the cylinder, 

 and is insulated from the rest of the instrument. The point is 

 connected with one of the poles of the voltaic battery, and the 

 cylinder with the other. On to the cylinder of one of the instru- 

 ments the message to be transmitted is attached. The message is 

 written on tin-foil with varnish or other non-conducting substance, 

 and the electric circuit is completed whenever the point is resting 

 on the tin-foil, and is interrupted when the point rests on the var- 

 nish writing. On the cylinder of the receiving instrument paper, 

 saturated with a scdution which electricity will easily decompose, 

 is placed ; and as a similar metal point presses upon it, whenever 

 the electric circuit is completed, by passing from the point to the 

 paper, a mark is made. Thus, by the revolution of the cylinders, 

 and the traversing of the nuts, spiral lines very close together are 

 drawn on the paper; but the circuit being interrupted when the 

 point of the transmitting instrument rests on the varnish, those 

 parts remain white. In this manner, if the transmitting and re- 

 ceiving instruments be moving exactly together, the point of the 

 former, by passing several times over each line of writing, will 

 cause the marking point to produce the forms of the letters on the 

 paper, the writing appearing white on a dark ground, constituted 

 of numerous fine lines. 



It is essential that the corresponding instruments should move 

 synchronously. To effect this, the patentee employs electro-mag- 

 nets, to regulate at certain intervals the continuous rotations of 

 the cylinders. Several methods by which this may be done are 

 noticed, but the mode preferred is to use pendulums actuated by 

 clock-work, which at each vibration strike against moveable wires 

 or fine springs, that serve to bring the electro-magnets into action, 

 by completing the circuit with local voltaic batteries, one of which 

 is attached to each instrument. The electro-magnets being thus 

 brought into action at each beat of the pendulums, they are made 

 to regulate the instruments, by causing a detent fixed to the keep- 

 ers to press against projections in the cylinders. The movement 

 of each cylinder is made rather faster than the resulting motion 

 required; and the distant instruments are regulated to keep to- 

 gether by retarding their movements in a slight degree each time 

 that the electro-magnets are put in action by the pendulums. As 

 a means of ascertaining whether they are moving synchronously, a 

 strip of paper is placed at right angles to the lines of writing on 

 the transmitting instrument; and this produces a corresponding 

 white mark on the paper, by which the operator is enabled to tell 

 with great exactness whether the pendulum of his instrument is 

 vibrating faster or slower than the other, and he can thus adjust it 

 to correspond. The starting of the two instruments is contrived 

 by means of an electro-magnet, put in action by the electric cur- 

 rent transmitted along the connecting wires. The keeper of the 

 magnet presses against the fan of the receiving instrument, and 

 when the circuit is momentarily interrupted by the starting of the 

 transmitting instrument, the keeper falls back and liberates the 

 fan. 



To copy print with these instruments, a portion of the printers' 

 ink may be transferred to tin-foil by pressure, or the foil may be 

 printed on from types. In copying small print, or small writing, 

 the cylinder of the receiving instrument should be larger than that 

 of the transmitting instrument, and the screw of the traversing 

 nut coarser, so as to produce a magnified copy of the original. 



The patentee describes a variation in the mode of copying, by 

 using several points instead of one, so that several lines of writing 

 may be copied at the same time, the electricity being conducted 

 rapidly from point to point in succession. The rapidity with which 

 the copying process may be carried on may be inferred from the 

 size of the cylinder and the rapidity of its revolutions. The dia- 



meter of the cylinder appears from the drawings to be about six 

 inches, and it is stated that it may be regulated to make thirty re- 

 volutions in a minute, and that seven times traversing over each 

 line of writing is sufficient for copying distinctly. On a cylinder 

 six inches diameter, about one hundred letters might be written in 

 a line, and that would amount to more than four hundred letters 

 per minute, with a single wire. In consequence of this rapidity of 

 action, the patentee says that the copying telegraph affords pecu- 

 liar facilities for establishing a system of stated transmissions and 

 deliveries throughout the day; every half-hour being named as the 

 interval between the communications with each town in the cir- 

 cuit. 



Fig. I. 



The annexed woodcut (Fig. 1) represents a plan of the copying 

 instrument. I, I, represent the frame containing the train of 

 wheels for giving motion to the cylinder C; D, the drum from 

 which the weight is suspended ; and F, the fan which prevents ac- 

 celeration. S, tlie screw on which the nut, N, traverses, carrying 

 the point P; M, the regulating electro-magnet; L, the keeper 

 and the connecting lever which presses against the projections E, 

 E, to retard and regulate the motion of the cylinder. To the 



clock-plate p, from which the pendulum B (seen in section) is sus- 

 pended, there are fixed ivory brackets h, h, which support platinum 

 wires c, c, fixed to a cross wire o, that slides easily on the brackets. 

 The wires from the voltaic battery r, are connected with the clock-. 



29 



